1. Field of the Invention
This invention relates to endoscopes, and more particularly to an endoscope which can be wholly immersed in a washing liquid or an antiseptic solution.
2. Description of the Prior Art
Endoscopes are divided into two types including endoscopes for the medical purpose to observe cavities in a body such as a stomach, a duodenum, a bronchus and the like and endoscopes for the industrial purpose to observe the interiors of a machine or component such as an engine. Each of these endoscopes is generally constructed as shown in FIG. 1. More specifically, referring to FIG. 1, reference character A designates an endoscope comprising: an insertable portion 1 to be inserted into a portion to be observed in the cavity of body, or the machine or component; a manual control portion 3 connected to the proximal end of the insertable portion 1 and having an ocular portion 2 and the like; and a connecting portion 5 connected at the proximal end thereof to the manual control portion 3 and detachably connected to an external apparatus B through a connector 4 provided at the forward end thereof. The interiors of the cavities of body and the machine or component can be observed through the ocular portion 2, and further, a camera C for recording observed images can be installed onto the ocular portion 2.
The endoscope A generally constructed as described above transmits an irradiating light from a lamp of xenon, halogen or the like provided in the external apparatus B to the forward end of the insertable portion 1 to irradiate the interior of an object to be observed through optical fibers for transmitting the irradiating light, which are provided in the connecting portion 5, manual control portion 3, insertable portion 1, so that, through an observation optical system including an objective optical system, optical fibers fcr transmitting images, an ocular optical system as arranged in the above-described order from the forward end of the insertable portion 1, the object is observed through the ocular portion 2 or photographed by means of the camera C coupled to the ocular portion 2.
In order to take a photograph with the camera C, in the endoscope A between the ocular portion 2 coupled thereonto with the camera C and the connector 4 as being a connection to the external apparatus B, there are incorporated a power cable for the power supply to an electric circuit of the camera C from the external apparatus B and a signal cable for the signal delivery to an exposure control portion of the external apparatus from the camera C. In consequence, a plurality of electrode terminals are exposedly provided on the ocular portion 2 and the connector 4, respectively.
The above-described arrangement is the general arrangement belonging to the endoscopes well known so far. Recently, necessity has been voiced for the capabilities of being washed and disinfected of the endoscopes with the above-described arrangement, particularly, ones for the medical purpose from the viewpoint of sanitation. In general, it is said that liquid washing and liquid disinfection are most simple and perfect as the washing and disinfection applied to the endoscopes. In consequence, the endoscopes capable of being wholly immersed in such solutions as described above should be the endoscopes having the most desirable arrangement. However, in the conventional endoscope, although the insertable portion is perfectly waterproof, the electrode terminals on the ocular portion and the connector are exposed. Therefore, once the ocular portion or the connector portion is moistened, it becomes difficult to drain and dry the moistened portion, thus presenting such a disadvantage that the endoscope cannot be used immediately after the washing and disinfecting the endoscope.
In consequence, in the endoscopes, which have been proposed and put to the practical use, in order to obviate the aforesaid disadvantages, there have been taken such measures that a cover member is provided for water-tightly covering some portions of the electrode terminals, i.e. portions not desirable to be immersed in a liquid during the immersion of the endoscope in the liquid, or shapes of such portions as described above are changed and an adapter is utilized when such portions are connected to the external apparatus or the like, thereby resulting in inconvenience in handling.